See Also: MK3Mag, MKGPS

NaviCtrl, MK3Mag und MKGPS

Overview

The NaviCtrl together with the MK-GPS and MK3Mag extend the abilities of the Mikrokopter.
Functions such as PositionHold or ComingHome are therefore now possible.

Besides an ARM9-Mikrocontroller and Mikro-SD-Card-Socket, the NaviCtrl-Board is also equipped with expansion sockets for future developments.

The development of the software is still in its early stage. Further functions such as logging of flight data onto the SD-Card and more will soon be available...

First Steps

Assembly of final parts

The following items are included with the NaviCtrl and need to be assembled by yourself:

• 1 Electrolyte Capacitor (C1, check polarity!)

• 2 Pin Rows (1x 10pole for FlightCtrl, 1x6pole for SPI-Interface)

• Multistrand ribbon for connection to MKGPS with fitted plugs

• 2 Multistrand ribbon (1x 10pol and 1x6pol for connection with FlightCtrl)

Optional (Not included):

• 1 Pin Row for Debug (1x 10pole, e.g. for Software-Update)

Installation Instructions

Install the NaviCtrl so that the 6 pole connector is above the 6 pole connector of the FC and the 10 pole connector is above the 10 pole connector of the FC.

Use the 10 pole and 6 pole Ribbon to connect to the Flight Ctrl.

NaviCtrl-SV8 <-> FlightCtrl-SV1 and
NaviCtrl-SV6 <-> FlightCtrl-SV5

For installation of the MK3Mag and MKGPS please follow instructions under MK3Mag and MKGPS.

Settings

Kompass and GPS must be activated in the relevant settings.

Parameters for GPS-Naviboard in Koptertool (Tab1)

GPS-Gain (Controller Gain)

This sets, how strong the GPS should influence. If it is too high, the position will swing. The value should be determined experimentally by assigning this setting to a Poti (adjustable auxiliary channel on transmitter).

Stick Threshold

This can be used to adjust the threshold for GPS-AID, where a new position will be logged.

Useful: If the value is set to 0, it will not log using stick postition, but only by switching the Mode-Switch

Fly to the desired position and switch to AID. You can then play with the sticks and the MK will still continue to return to its set position. Especially in windy conditions this can be used to prevent that the MK even starts to drift.

Min Sat

Minimum number of satellites that need to be detected by the GPS receiver.

Parameter GPS-P

P-component of the Control

Influence of the GPS-distance on the controller (Higher Value = greater tilting during drift from a position)

Parameter GPS-I

I-component of the Control

Elliminated the constant positional drift during wind (Higher Value = greater tilting during prolonged positional drift)

Parameter GPS-D

D-Component of the Control

Influence of the GPS-Speed on the Controller (Higher Value = Slower movement)

Parameter GPS ACC

Support of positioning with the Acc sensors. If the MK is pushed away it will react faster.

--> Slowly and gradually work towards higher values(use Poti)

Parameters for GPS-Naviboard in Koptertool (Tab2)

(Screenshot Mikrokopter-Tool v1.63)

ToDo: complete descriptions

GPS Wind Correction

Because of cross-winds a deviation from actual heading to the set heading can be created. With this parameter a correction angle is taken to minimize the deviation. It controlls the amount of influence of this compensation. A value of 0 means the function is turned of.

Speed Compensation

This is the "D-Anteil" during a break-phase in GPS_MODE_AID after manual intervention. A higher value makes the MK break harder after a manual control before he sticks to the set-position.

GPS Max Radius

This value defines a circle shaped area around the starting position. Only inside this area position-targets (like waypoints) can be set. If the position is outside of this area, the target will be set onto coordinates on this radius which are the closest to the "outside"-target. The maxiumum length of this radius is 255meters. This is equal to an area of 512m in diameter around the point where the motors of the MK were started.

notice: for PositionHold(PH) there is no range limit (using latest firmware)

GPS Angle Limit

delimits the maximum influence of the GPS. A value of 100 equals about 20 degrees of inclination in an axis. With a too small value it could happen that the MK will not be strong enough against winds and drift away. A too large value might end in a too high speed

Position Hold Login Time

delay in seconds between the end of manual control (nick/roll in neutral) and the sticking to the set position in GPS_MODE_AID.

GPS-Mode

There are 3 modes that can be selected with "GPS Mode Control". GPS_MODE_AID, GPS_MODE_FREE and GPS_MODE_HOME.
Here, you may select which channel of the transmitter is used to switch between modes

Since Firmware 0.74 the switch settings have been altered to GPS OFF - PH - CH (Previously it was PH - OFF - CH)
GPS_MODE_FREE (!GPS_Mode_Control < 20)

• No GPS effect
  
  

GPS_MODE_AID (or Position Hold) (!GPS_Mode_Control between 20 and 200)

• the GPS has a supportive effect
• The GPS-speed complements the pilots commands and where applicable acts with a slowing/braking effect.
• When no elevator or roll controls are given by the pilot, the MK will hold its current position.
• The new position will be logged when the MK falls below a certain speed or after no more than 4 seconds.
• A beep will indicate the logging of a new position

GPS_MODE_HOME (!GPS_Mode_Control > 200)

• Coming Home --> Fly back to originating position

• The position during the start of the motors is logged as Home

Warning: When ComingHome is used to fly back to yourself, the altitude control must be active otherwise it will drop down and may continue to accelerate down.

Tip: Generally the GPS will only work well when the altitude control is active. Otherwise the vertical accelerations brought by with the control movements will confuse the Acc-Sensors to much.

Tip2: Since 0.71c of FC Code and 0.12 of NC Code, you can combine GPS and Altitude Control Switch. Then Alt-Control is active <50 and >180. So in FREE Mode the Alt Control is off and in AID and PH it's on.

• When the LED on the GPS is flashing a FIX has been achieved.

Signal tones

With a correctly attached NaviCtrl, the FlightCtrl will now beep more often when either GPS_MODE_AID or GPS_MODE_HOME are selected. The tones communicate the following:

• beeping every 1 second *Beeep* - Until a minimum of 6 satellites has been found. It will become quieter when a FIX has been obtained but not yet 6 satellites found.
• Fast 5khz Beeping *Drrrr* - The MK is leaving its target coordinates by more than 15m (Also happens when the mode is switched to Coming home and the MK distances itself by 15m from target)
• 1x Beep *Beeep* - Logging of new target coordinates (about 2 second delay)

• When GPS_MODE_FREE is selected, GPS is off and there will be no beeping to indicate the satellite fix status.

LED-Display

The NaviCtrl has 2 LED’s, 1x red and 1x green. During the current program status, they chaotically flicker to signal the general program processing. The Blink code is random and is not a sign of faults.

How do you start?

1. You need a lot of space and a free sky

2. Checking the communication between Navi and FlightCtrl.

   • Beeping will continue as long as the GPS has no Fix
   • Once the GPS has a Fis, a beep will sound when changes are made with the mode switch
3. Wait for first Fix
   • Until LED on GPS start to flash
   • Beeping will continue every second until 6 satellites have been found
   • Beep is more quiet when a Fix has been obtained but still no 6 satellites found

4. Switch to GPS_MODE_FREE

   • Change of Mode will be indicated by a beep
5. Start Motors
   • Hover for a few seconds until the MK flies well without trimming.

6. Switch to GPS_MODE_AID

   • Position will be logged
   • GPS should now grab and the Kopter will hover at its position.

When the distance from the target point is exceeded by 15m, a quick beep of 5 times per second (5Hz) will sound.

How do I Install new software into the NaviCtrl ?

1. You solder a pin row on the Debug interface position of the NaviCtrl and connect this to the Sercon’s SIO position. Ensure that No Jumper is attached to the Sercon.

2. Connect the FC with the NaviCtrl using the 10 and 6 pole connectors. Now turn on the Mikrokopter.

3. Start Mikrokopter-Tool >=1.51 and click on Update Software (seriell). Select the .hex file.

4. The Update procedure starts and should be complete in about 1-2 minutes. After this you can see the arrival of debug data in the terminal.

What if installing new firmware went wrong?

If for some reason installing new firmware went wrong or was aborted, and NaviCtrl no longer responds to the Mikrokopter-Tool, retry installation using the sequence below:

1. Remove power from NaviCtrl.

2. Without power on NaviCtrl, click on Update Software (seriell) and select the appropriate .hex file.

3. Wait for the message Connecting (ggf. Resetten) to appear.

4. As soon as the message appears, power up NaviCtrl and the installation should start.

Circuit Scheme & Assembly diagram & bill of material

NaviCtrl/Navi-Ctrl_V1_1.pdf

MicroSD-card

• The NaviCtrl logs the flight route in KML format on FAT16 formatted MicroSD-cards up to 2GB in size.

• A recognized and initialized SD-card can be seen in the NaviCtrl initialization messages.

• 

BOM: NaviCtrl/Navi-Ctrl_V1_1_Stueckliste.txt

How do I update new NaviCtrl software ?

1. You solder a pin header to the debug interface on the NaviCtrl and connect it to the SerCon's SIO interface. Make sure the jumper on the SerCon is removed.

2. Connect the FlightCtrl's 10-pin and 6-pin connectors with the NaviCtrl. Turn on the Kopter.

3. Start the Mikrokopter-Tool (version >=1.51) then click Update Software (seriell). The .hex data is then transferred.

4. The update starts and takes about 1-2 minute to complete. At the end you can see the debug data in the terminal.

Note that if the serial communication is interrupted during the transfer, the next attempt may hang. To overcome this, just switch the MK's power off then on when the message "" appears.

If there are several successive Firmware updates to be made, the sequence plays a role. Program the devices in the following sequence:

1. Navi-Ctrl_STR9_V0_14e.hex

2. Flight-Ctrl_MEGA644_V0_72p.hex

3. MK3Mag_MEGA168_V0_21b_SVN48.hex

Debug interface and KopterTool

Solder a pin header to the Debug interface of the NaviCtrl and connect this to the Sercon's SIO interface. Make sure there is no Jumper on the Sercon. Switch on the MK and start the KopterTool.

In the terminal mode, you should see the starting sequence of the NaviCtrl:

The last lines are the Debug data, they can be ignored. Here you can see whether all the interfaces and/or devices are correctly initialized.

In the Koptertool the NaviCtrl parameters are then available:

Screenshot of the main parameters:

• GPS-Data Counter: the GPS connection state is indicated (GPS count should increase)

• SPI Error and SPI Okay: the SPI connection to the FlightCtrl is indicated (Okay count should increase)

• Poti1,2,3: the transmitter potentiometer values can be checked
• ACC, angle, etc. is probably self explaining

The parameters can also be displayed in the Scope when connecting the FlightCtrl. A "setup" for the NaviCtrl is not possible (the button is grayed out).

ToDo: A few more things need to be added here

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